1. Field of the Invention
The present invention relates to a compressor including an oil separator for separating a lubricating oil contained in a working fluid.
2. Description of the Related Art
A compressor of this type is used, for example, in a refrigeration circuit of an air conditioner for a vehicle. The compressor used in the refrigeration circuit includes a compression unit in its housing. The compression unit sucks therein a cooling medium as a working fluid and compresses the cooling medium sucked therein. The cooling medium thus compressed is fed from a discharge port provided in the housing toward a condenser of the refrigeration circuit and circulates in the refrigeration circuit.
In general, the cooling medium in the refrigeration circuit contains a lubricating oil. The lubricating oil lubricates a sliding surface, a bearing and the like within the compressor, and is also useful for sealing the sliding surface within the compressor. However, since a large amount of lubricating oil in the cooling medium causes reduction in cooling ability of the refrigeration circuit, an oil separator is incorporated in the compressor of this type. After having guided the cooling medium compressed by the compression unit to separate a part of the lubricating oil from the cooling medium, the oil separator guides the cooling medium toward the discharge port.
More specifically, the oil separator includes a cylindrical separation chamber having an introduction port in its inner peripheral surface. A separation tube is disposed concentrically within the separation chamber. The cooling medium which is introduced into the separation chamber through the introduction port after having been compressed by the compression unit revolves and flows helically around the separation tube along the inner peripheral wall of the separation chamber. In this process, a part of the lubricating oil contained in the cooling medium is centrifuged to be separated from the cooling medium. The cooling medium which has been subjected to the separation processing is fed toward the discharge port through the separation tube, while the separated lubricating oil is discharged from the separation chamber to an oil storage chamber to be stored in the oil storage chamber.
In the case where the compressor has the above-mentioned oil separator built therein, it can cause the cooling medium in which the amount of lubricating oil is moderately reduced to circulate in the refrigeration circuit. As a result, it is possible to avoid the reduction in cooling ability due to an excessive amount of lubricating oil.
In the compressor including the oil separator as described above, an insertion hole is formed in the housing for the purpose of disposing the separation tube within the separation chamber. The separation tube is inserted through the insertion hole to be attached to the separation chamber, and fixed to the housing with a snap ring or the like. Thereafter, a seal bolt is screwed into the insertion hole to close the insertion hole, thereby preventing the cooling medium from leaking from the insertion hole.
For this reason, the performance of the compressor is enhanced from the attachment of the oil separator. However, the parts such a the separation tube, the snap ring and the seal bolt are added to increase the number of assembly processes. As a result, such configuration involves a problem that the part cost and the assembly cost increase.
As one of measures for solving such a problem, Japanese Unexamined Patent Publication No. 2001-295767 (hereinafter referred to as Patent Document 1) proposes a compressor in which a separation tube and a discharge port are integrated with each other so that the separation tube can be disposed in a separation chamber without providing an insertion port.
In the case of an oil separator disclosed in Patent Document 1, since a discharge port is formed in one end of the separation tube, assembly of the oil separator is completed by only attachment of the separation tube to the separation chamber.
However, in the case of the compressor disclosed in Patent Document 1 described above, the discharge port is disposed coaxially with the separation tube, and the separation tube is pressed against the housing side through a distal end portion of a cooling medium pipe to be fixed thereto. For this reason, the position of the discharge port is limited to an axial direction of the separation chamber. As a result, there is a program that the degree of freedom of disposition of the discharge port is limited, and moreover the installation place and direction of the compressor are limited.